def step(self, step=None):
""" Does one simulation time step."""
activearrays = self.pre_step(step)
# First construct complete hessian from reduced
h0 = red2comp(activearrays["hessian"], self.im.dbeads.nbeads, self.im.dbeads.natoms, self.im.coef)
# Add spring terms to the physical hessian
h1 = np.add(self.im.h, h0)
# Get eigenvalues and eigenvector.
d, w = clean_hessian(h1, self.im.dbeads.q, self.im.dbeads.natoms,
self.im.dbeads.nbeads, self.im.dbeads.m, self.im.dbeads.m3, self.options["hessian_asr"])
# d,w =np.linalg.eigh(h1) #Cartesian
info('\n@Nichols: 1st freq {} cm^-1'.format(units.unit_to_user('frequency', 'inversecm', np.sign(d[0]) * np.sqrt(np.absolute(d[0])))), verbosity.medium)
info('@Nichols: 2nd freq {} cm^-1'.format(units.unit_to_user('frequency', 'inversecm', np.sign(d[1]) * np.sqrt(np.absolute(d[1])))), verbosity.medium)
info('@Nichols: 3rd freq {} cm^-1'.format(units.unit_to_user('frequency', 'inversecm', np.sign(d[2]) * np.sqrt(np.absolute(d[2])))), verbosity.medium)
#info('@Nichols: 4th freq {} cm^-1'.format(units.unit_to_user('frequency','inversecm',np.sign(d[3])*np.sqrt(np.absolute(d[3])))),verbosity.medium)
#info('@Nichols: 8th freq {} cm^-1\n'.format(units.unit_to_user('frequency','inversecm',np.sign(d[7])*np.sqrt(np.absolute(d[7])))),verbosity.medium)
# Find new movement direction
if self.options["mode"] == 'rate':
f = activearrays["old_f"] * (self.im.coef[1:] + self.im.coef[:-1]) / 2
d_x = nichols(f, self.im.f, d, w, self.im.dbeads.m3, activearrays["big_step"])
elif self.options["mode"] == 'splitting':
d_x = nichols(activearrays["old_f"], self.im.f, d, w, self.im.dbeads.m3, activearrays["big_step"], mode=0)
# Rescale step if necessary
if np.amax(np.absolute(d_x)) > activearrays["big_step"]:
info("Step norm, scaled down to {}".format(activearrays["big_step"]), verbosity.low)
d_x *= activearrays["big_step"] / np.amax(np.absolute(d_x))
# Get the new full-position
d_x_full = self.fix.get_full_vector(d_x, t=1)
new_x = self.optarrays["old_x"].copy() + d_x_full
self.post_step(step, new_x, d_x, activearrays)
print("We can not recognize the mode. STOP HERE")
sys.exit()
# ----------------------------------------------------------START----------------------------------------------
beta = 1.0 / (kb * temp)
betaP = 1.0 / (kb * (nbeads) * temp)
print(("\nTemperature: {} K".format(temp / K2au)))
print(("NBEADS: {}".format(nbeads)))
print(("atoms: {}".format(natoms)))
print(("ASR: {}".format(asr)))
print(("1/(betaP*hbar) = {:8.5f}".format((1 / (betaP * hbar)))))
if not quiet:
print("Diagonalization ... \n\n")
d, w, detI = clean_hessian(h, pos, natoms, nbeads, m, m3, asr, mofi=True)
print("Final lowest 10 frequencies (cm^-1)")
d10 = np.array2string(
np.sign(d[0:10]) * np.absolute(d[0:10]) ** 0.5 / cm2au,
precision=2,
max_line_width=100,
formatter={"float_kind": lambda x: "%.2f" % x},
)
print(("{}".format(d10)))
if case == "reactant":
Qtras = ((np.sum(m)) / (2 * np.pi * beta * hbar ** 2)) ** 1.5
if asr == "poly":
Qrot = (8 * np.pi * detI / ((hbar) ** 6 * (beta) ** 3)) ** 0.5
else:
def step(self, step=None):
""" Does one simulation time step."""
activearrays = self.pre_step(step)
fff = activearrays["old_f"] * (self.im.coef[1:] + self.im.coef[:-1]) / 2
f = (fff + self.im.f).reshape(self.im.dbeads.natoms * 3 * self.im.dbeads.nbeads, 1)
banded = False
banded = True
if banded:
# BANDED Version
# MASS-scaled
dyn_mat = get_dynmat(activearrays["hessian"], self.im.dbeads.m3, self.im.dbeads.nbeads)
h_up_band = banded_hessian(dyn_mat, self.im, masses=False, shift=0.000000001) # create upper band matrix
f = np.multiply(f, self.im.dbeads.m3.reshape(f.shape)**-0.5)
# CARTESIAN
# h_up_band = banded_hessian(activearrays["hessian"], self.im,masses=True) # create upper band matrix
d = diag_banded(h_up_band)
else:
# FULL dimensions version
h_0 = red2comp(activearrays["hessian"], self.im.dbeads.nbeads, self.im.dbeads.natoms, self.im.coef)
h_test = np.add(self.im.h, h_0) # add spring terms to the physical hessian
d, w = clean_hessian(h_test, self.im.dbeads.q, self.im.dbeads.natoms,
self.im.dbeads.nbeads, self.im.dbeads.m, self.im.dbeads.m3, None)
# CARTESIAN
# d,w =np.linalg.eigh(h_test) #Cartesian
info('\n@Lanczos: 1st freq {} cm^-1'.format(units.unit_to_user('frequency', 'inversecm', np.sign(d[0]) * np.sqrt(np.absolute(d[0])))), verbosity.medium)
info('@Lanczos: 2nd freq {} cm^-1'.format(units.unit_to_user('frequency', 'inversecm', np.sign(d[1]) * np.sqrt(np.absolute(d[1])))), verbosity.medium)
info('@Lanczos: 3rd freq {} cm^-1\n'.format(units.unit_to_user('frequency', 'inversecm', np.sign(d[2]) * np.sqrt(np.absolute(d[2])))), verbosity.medium)
if d[0] > 0:
if d[1] / 2 > d[0]:
alpha = 1
lamb = (2 * d[0] + d[1]) / 4
else:
alpha = (d[1] - d[0]) / d[1]
lamb = (3 * d[0] + d[1]) / 4 # midpoint between b[0] and b[1]*(1-alpha/2)
elif d[1] < 0: # Jeremy Richardson
if (d[1] >= d[0] / 2):
alpha = 1
lamb = (d[0] + 2 * d[1]) / 4
else:
alpha = (d[0] - d[1]) / d[1]
lamb = (d[0] + 3 * d[1]) / 4
# elif d[1] < 0: #Litman for Second Order Saddle point
# alpha = 1
# lamb = (d[1] + d[2]) / 4
# print 'WARNING: We are not using the standard Nichols'
# print 'd_x', d_x[0],d_x[1]
else: # Only d[0] <0
alpha = 1
lamb = (d[0] + d[1]) / 4
if banded:
h_up_band[-1, :] += - np.ones(h_up_band.shape[1]) * lamb
d_x = invmul_banded(h_up_band, f)
else:
h_test = alpha * (h_test - np.eye(h_test.shape[0]) * lamb)
d_x = np.linalg.solve(h_test, f)
d_x.shape = self.im.dbeads.q.shape
# MASS-scaled
d_x = np.multiply(d_x, self.im.dbeads.m3**-0.5)
# Rescale step if necessary
if np.amax(np.absolute(d_x)) > activearrays["big_step"]:
info("Step norm, scaled down to {}".format(activearrays["big_step"]), verbosity.low)
d_x *= activearrays["big_step"] / np.amax(np.absolute(d_x))
# Get the new full-position
d_x_full = self.fix.get_full_vector(d_x, t=1)
new_x = self.optarrays["old_x"].copy() + d_x_full
self.post_step(step, new_x, d_x, activearrays)
